What is fuel ?
The substances which produce heat energy on burning are called fuels.
ICSE
What is chemistry ?
“The branch of science that deals with the study of the composition and physical and chemical properties of various forms of matter is called Chemistry.”
What is science ?
It is the systematic effort by human beings to control nature through experiments and observation for their use.
What are Preservatives?Explain.
Preservatives are the chemicals which maintain the taste for longer time and do not let the food degrade to produce obnoxious (unpleasant smell), e.g. sugar, common salt, sodium benzoate and sodium meta-bisulphate.
What are Enzymes?
Enzymes are the chemicals secreted by our body which react with food water and oxygen as raw material in our mouth and intestines.
What are Hormones?
Hormones are group of chemicals secreted in our body to control various activities.
What is Fungicides?
Fungicides are the substances which protect crops from fungi, e.g. Bordeaux mixture and sulphur act as fungicides.
What do you mean by Insecticides?
Insecticides are the chemical used to kill insects, e.g. B.H.C.
What are fertilisers?
Fertilisers are the chemicals which provide nutrients to crops and increase their yeild.’e.g. calcium nitrate, potash, ammonium sulphate etc.
What is external fertilisation ?
Solution : The fusion of a male and a female gamete takes place outside the body of the female is called external fertilisation. It is very common in aquatic animals such as fish, starfish, etc.